Well cementing plug



Dec. 15, 1953 R, c. BAKER ET AL WELL CEMENTING PLUG 2 Sheets-Sheet l Original Filed Jan. 12, 1948 Reuse/v C. BAKER, 'C70/wv R. BAKER,

INVENTORS.

A77- TOQA/Eys.

Dec. 15, 1953 R. c. BAKER ET AL 2,662,600

WELL. CEMENTING PLUG Original Filed Jan. 12, 1948 2 Sheets-Sheet 2 @EL/BEN C. BAKE/i2 z7HN A?. 54H5@ 1N VEN T ORS rroeA/Egs. l

Patented Dec. 15, 1953 WELL CEMENTING PLUG Reuben C. Baker, Coalinga, and John R. Baker, l Pasadena, Calif., assignors to Baker Oil Tools, Inc., Vernon, Calif., a corporation of California Original application January 12, 1948, Serial No. 1,844. Divided and this application November 14, 1949, Serial No. 127,188

8 Claims.

The present invention relates to well devices, and more particularly to plugs adapted to prevent comingling between luent cementitious materials and other iluids in the well casing, or other conduit string, through which the plug is pumped.

This application is a division of our application for Side Ported Cementing Apparatus, Serial No. 1,844, filed January 12, 1948, now Patent No. 2,633,916.

An object of the present invention is to provide an improved cementing plug capable of preventing comingling between fluent cementitious materials and other well fluid pumped down the casing string and the like, and which can also function as a valve member in preventing fluid ow through a sleeve valve or other restriction in the casing string.

Another object of the invention is to provide a cementing plug that is particularly useful in connection with the shifting of a sleeve valve to closed position across the ports of a conduit apparatus located in a well bore.

A further object of the invention is to provide a top cementing plug that can function as a valve in closing the passage through a sleeve valve or the like disposed in a casing string, the plug being capable of allowing fluid to by-pass it for the purpose of hydraulically actuating another member, such as another sleeve valve.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It

lwill now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best dened by the appended claims.

Referring to the drawings:

Figure 1 is a longitudinal section through a ported well apparatus, with the ports closed and the parts arranged for running the apparatus in a well bore;

Fig. 2 is a view similar to Fig. 1, disclosing the apparatus after the ports have been opened and with other parts occupying a position fo reclosing the ports;

Fig. 3 is a view similar to Fig. 2, with the ports reclosed; V

Fig. 4 is an enlarged longitudinal section', with parts in elevation, of a. top cementing plug par- 2 ticularly useful in connection with the casing apparatus disclosed in the drawings.

AS disclosed in the drawings, a casing collar A has its upper and lower ends threadedly connected to the ends of upper and lower casing sections B, C, forming part of a casing string adapted to be run in a well bore to position the collar at the desired location therein.

The collar includes a tubular member I l) whose lower end. consists of a coupling I I threaded onto the upper end of the lower casing section C. A stop member I2 is secured to the exterior of the coupling', as by the use of welding material i3, to serve a purpose described below.

rEhe tubular member I0 has a plurality of circularly spaced side ports I4 through which fluids are adapted to pass between the interior and exterior of the collarapparatus. These ports are closed initially by a lower inner sleeve valve member I5 having seal rings IS, I1 disposed in suitable ring grooves I8 on opposite sides of the ports. These rings may be of rubber and of round cross-section to prevent leakage thereby in both longitudinal directions.

The lower inner sleeve valve member I5 is retained in position to locate its seal rings I6, I'I on opposite sides of the ports I4 by one or more frangible devices in the form of shear screws I9 threaded through the tubular member I0 and extending into the valve member.

It is to be noted that thel inside diameter of the tubular member Ill at the region where it is `engaged by the lower seal ring I1 is less than the internal diameter of a groove 23 in the member IE! immediately below this region.A Also, the sleeve valve member I5 is reduced in external diameter to form a peripheral groove 24 below the lower seal ring I?, in which a split, inherently expansible stop ring 25 is located. The Astop ring has an upper, inner inclined surface 25 tapering downwardly and inwardly for cooperation with a correspondingly tapered surface 27 on the base of the peripheral groove 24. rlhe length of the groove-24 is much greater than the lengthA of the Ystop ring, to permit downward movement of the sleeve valve member I5 relative to the stop ring.

rEhe ring 25 is "received within the enlarged diameter portion k23 of the tubular member, which enlarged portion is also much longer than the height of the stop ring.l The stop ring may :rest upon a shoulder 28 provided by the lower end of theperipheral groove 24, its upper end "being engageable with an upper shoulder '29 of '55 thefperipheralgroove 241m the valve member I5. Downward movement of the stop ring is limited by its engagement with a shoulder 30 formed by the lower end of the tubular member groove 23.

The shear screws I9 are adapted to be disrupted and the lower inner sleeve valve member I5 moved downwardly to a position in which the upper seal ring I6 is disposed below the ports I4. The ports are then open to the passage of fluid from the interior of the apparatus to its exterior.

After the ports have been opened, it is desired to reclose them. To accomplish this purpose, an external sleeve valve member 3| is provided on the tubular member. This external valve member has a plurality of longitudinally spaced seal rings 32, 33 disposed in its internal grooves 34, and slidably engageable with the outer surface of the tubular member I0. The outer member 3| has an upwardly extending cylinder 35 integral therewith, which is slidable along an enlarged portion Ila of the tubular member. The outer member 3| is retained initially in an upward position, in which it does not close the ports I4, by one or more shear screws 3B threaded through the cylinder 35 into the enlarged portion Illa of the tubular member. These screws are disruptable hydraulically by fluid pressure entering through one or more ports or openings 31 in the tubular member into a cylinder space 38 provided between the enlarged portion Illa of the tubular member, the cylinder skirt 35 and the portion 3Ia of the sleeve valve member' carrying the seal rings 32, 33. Leakage in a downward direction between the sleeve valve member 3| and tubular member Il is prevented by the seal ring 32. Leakage in an upward direction therebetween is prevented by a seal ring 39 disposed in a peripheral groove 4l in the enlarged portion Ila of the tubular member, which sealingly engages the inner surface of the cylinder 35.

When fluid under pressure of a suflicient degree is allowed to enter through the ports 31 into the cylinder space 38, the shear screws 36 will be disrupted and this fluid pressure will shift the outer sleeve valve member 3| downwardly to a position in which its seal rings 32, 33 are disposed on opposite sides of the ports I4, closing such ports against passage of fluids therethrough in both directions between the interior and exterior of the apparatus. This position of the sleeve valve member 3| is determined by engagement of its depending skirt 4I with the upper end of the stop member I2 welded onto the tubular member coupling II. It is to be noted that the skirt 4I is spaced outwardly from the tubular member In so as to avoid interfering with passage of fluids through the ports I4 after they have been opened.

After the outer sleeve valve member 3| has been shifted downwardly to port closing position, it is prevented from moving upwardly again by a latch or lock ring 42 disposed within a peripheral groove 43 in the tubular member I9 above its seal ring 39. This lock ring consists of a split, inherently expansible member having a reduced diameter lower portion 42a, forming a shoulder 44 with the upper portion 42h, which is inclined outwardly in a downward direction to a slight extent. When the outer sleeve valve member 3| has been forced downwardly to its fullest extent, the upper end 35a of the cylinder will be disposed below the shoulder 44 of the split lock ring, but not below the lower'end of its reduced diameter portion 42a (see Fig. 3). As a matter of fact, the upper part of the cylinder 35 will be in engagement with the outer surface of the reduced' diam`- eter portion 42a, the lock ring 42 inherently expanding outwardly to a certain extent upon riding of the cylinder off its upper portion 42h (Fig. 5). Any tendency for the outer sleeve valve member 3| to move upwardly will be limited by engagement of the upper cylinder end 35a with the lock ring shoulder 44, the lock ring being forced against the upper end of the peripheral groove 43. To insure against inward forcing of the lock ring 42 from engagement with the end 35a of the cylinder, the latter is tapered in the same direction as the shoulder 44, so that the two will remain in snug contact with one another,

At first, fluid under pressure is prevented from passing through the openings 31 into the cylinder space 3l by an upper inner sleeve valve member 45 having longitudinally spaced seal rings 46 disposed in ring grooves 41 on opposite sides of the ports 31. This valve member is held in such position by one or more shear screws 48 threaded through the tubular member I0 into the upper valve member 45. Disruption of the shear screws 48 and downward shifting of the upper sleeve valve member 45 will open the ports 31 and permit fluid under pressure to pass through the latter into the cylinder space 38, in order to shear the cylinder screws 36 and move the outer sleeve valve member 3| downwardly to port closing position.

As stated above, the lower sleeve valve member I5 is held initially in closed position by its shear screws I9. Similarly, the upper sleeve valve member is held in closed position over the cylinder ports 31 by its shear screws 48, preferably closely adjacent, or in abutting relation with, the lower valve member I9. The upper valve member 45 has a central bore 49 whose wall tapers downwardly and inwardly. Similarly, the lower valve member I5 has a downwardly and inwardlyI tapering central bore 50, which, in effect, forms a continuation of the upper member bore 49. The cylinder screws 36 hold the outer valve member 3| in its upper position, the parts all being arranged as illustrated in Fig. 1, occupying positions for lowering the apparatus into a well bore.

With both sets of ports I4, 31 closed, fluids, such as cement slurry, may be pumped directly into the casing string and through the central bores or passages 49, 50 in both sleeve valve members 45, I5 for discharge from the well casing at some point below the collar, as, for example, from a casing shoe (not shown). This charge of cement slurry will pass upwardly through the annulus around the casing string and may extend approximately to the location of the collar A. or slightly thereabove.

When it is desired to eject a second charge of cement slurry through the collar ports I4, a trip device or plug member 5| is dropped into the well casing, vand is allowed to gravitate through the fluid therein into engagement with the wall of the central bore 50 in the lower inner sleeve valve member I5. As disclosed in the drawings, this trip device may consist of a substantially spherical Atrailing head 52 having a lesser external diameter than the minimum diameter of the tapered bore 49 in the upper'sleeve member, to insure its complete passage through the latter. The spherical head, however, has a diameter greater4 than the'minimum diameter of the bore 50 through the lower valve member I5. As a result, the trip membercomes to rest within the lower valve member, with its head 52 closing its central bore or passage. Pressure may now be appliedto the fluidin the casing above the trip member I ofV an amount suflicient to shear the screws [9 and shift the lower sleeve valve member I5 downwardly to port opening position, as shown in Fig. 2. Downward movement of the lower valve member is' determined by engagement of the stop ring 25 with the shoulder 30 of the tubular member I 9 and of the shoulder 29 on the lower sleeve member with the stop ring. Washing iluid, followed by cement slurry, may now be discharged outwardly through the open ports I4, passing through the annular space 51 between the tubular member I0 and the depending skirt 4| of the outer valve member and thence upwardly through the annulus around the tubular member and casing string.

Upon discharging the required quantity of cement slurry, the outer sleeve valve 3I is forced downwardly to port closing position. This act may be accomplished by placingv a top cementing plug 58. at the upper end of the charge of cement slurry pumped outwardly through the ports I4. This plug comes to rest partly within the bore 49 ofthe upper inner sleeve valve member 45, allowing the fluid in the casing string above the collar to be pressurized to a suiicient extent tov shear the screws 48 and shift the upper inner valve member downwardly to a position in which the cylinder ports 31 are open.r

The top cementing plug 58A disclosed in the drawings` is of a composite character. It includes a 1ower generally spherical head 59 on which a suitable, generally spherical rubber seal 60 is mounted. This seal is held in position by the reception of its internal flange 64I within a peripheral groove 62 in the head. The head has an upwardly extending tail piece 63 extending within the centrally disposed socket 64 of a flexible cementing plug 65. These two parts are secured to one another by a metallic band 66 embracing the forward neck portion 61 of the plug 65, foroing its inwardly directed flange 68 into a companion peripheral groove 69 in the tail piece 63.

The exible plug 65 is formed essentially of rubber or similar material. It has an inwardly compressible body portion 10 defined by tapered forward and rearward surfaces 1I, 12, merging into an annular peripheral sealing surface 13 slidably engageable with the wall of the well casing. The plug 65 has a tail portion 14 terminating in a fluted guide 15. Its annular sealing portion 13 has an upwardly extending lip 15a adapted to be forced outwardly by lluid pressure against the wall of the casing.

The generally spherical seal 60 on the upper cementing plug head 59 has a diameter greater than the minimum diameter through the upper sleeve 45. As a result, this seal will come'to rest within the tapered bore 49 of the latter, closing it against passage of fluid and allowing pressure to be built up in the casing fluid above the cementing plug 58 Sufficient in extent to shear the screws 48 and shift the upper member 45 downwardly to a position on top of the lower sleeve I5, opening the cylinder ports 31 (see Fig. 2).

Fluid under pressure may now be directed outwardly through the cylinder ports 31 into the cylinder 35 for the purpose of shearing the cylinder screws 36 and moving the outer sleeve 3I downwardly to port closing position, such as disclosed in Fig. 3.

A standard top cementing plug would not permit fluid to pass by it and enter the ports 31. The flexible plug 65 described above, however, will have its body 10 and annular sealing portion 13 deformed inwardly to a sufcient extent, upon application ofsumcient pressure thereto, to allow the fluid to pass'around it and enter the ports 31, in order to shift the' outer sleeve valve member 3| to its port closing position. Afterthe latter has been so shifted, and the pressure of the fluid in the casing string bled olf, the hydrostatic head of cement slurry in the casing annulus would tend to shift the sleeve valve 3l upwardly again to port opening position. This tendency is prevented, however, by engagement of the upper end 35a of the cylinder with the shoulder 4t` on the latch ring 42, and by the abutting of the latter with the upper side of the peripheral groove 43.

After the cement has set and hardened, all parts within the. tubular member' can be disintegrated by a drilling bit. To facilitate this action, all internal mechanism is preferably made of readily drillable materials, including the cementing plug head 59 and tail 63, both inner sleeve valve members I5, 45, the stop ring 25, and thetrip device 5 I. Such materials may be magnesium, cast iron. aluminum and the like. During the drilling-out operation, the drilling bit cannot act upon any movable parts which are tol remainv within the tubular member I9', since none are present. Accordingly, there isv no tendency for the ports' I4 to be reopened inadvertently, since the external sleeve valve member 3f cannot be contacted by the drill bit.

It is, accordingly, apparent that a combination top cementing plug and valve member has been disclosed, which is capable of preventing the displacement fluid on. top of the cementing plug from comingling with the column of cement slurry therebelow. Thecementing plug also seats in the valve seat. 45 to open the ports 31 leading into the cylinder space 3'8.. The ability ofthe cementing plug 65 to be compressed and deformed inwardly allows fluid to by-pass around its exterior, for the purpose of owing through the open ports 31, to shift the outer sleeve valve member 3I downwardly to a position closing the ports I4.

The inventors claim:

1. A top cementing plug, including a forward rigid valve head portion and an elastic rearward portion secured to said head portion and having an inwardly compressible main body, said body having an annular flange adapted for slidable sealing engagement with the wall of a well conduit, and a trailing portion having an outer surface converging in a direction leading away from said head portion to be acted on by hydraulic pressure to compress said body inwardly and remove said flange from sealing engagement with the wall of the well conduit.

2. A cementing plug, including a forward rigid valve head portion having a rearwardly extend ing tail piece, an elastic inwardly compressible body having a central socket receiving said tail piece, said body being adapted for slidable sealing engagement with the wall of a well conduit, and a band encompassing said body for securing said body to said tail piece.

3. A top cementing plug, including a forward rigid head portion, an elastic rearward portion secured to said head portion and having an inwardly compressible main body, said body being adapted for slidable sealing engagement with the wall of a well conduit and being compressible inwardly by hydraulic pressure out of such sealing engagement, and an elastic generally spherically curved seal on the forward surface of said head portion.

4. A top cementing plug, including a forward aeeaooo generally spherlcallycurved head portion, a tail piece secured to and extending rearwardly from said head portion, an elastic rearward portion having an inwardly compressible main body provided with a socket receiving said tail piece, said body being adapted for slidable sealing engagement with the wall of a well conduit and being compressible inwardly by hydraulic pressure out of such sealing engagement.

5. A top cenienting plug, including a forward rigid head portion, a tail piece rigidly secured to and extending rearwardly from said head portion, an elastic inwardly compressible main body having a socket receiving said tail piece, said body being adapted for slidable sealing engagement with the wall of a well conduit and being cornpressible inwardly by hydraulic pressure out of such sealing engagement, and an elastic generally spherically curved seal on the forward surface of said head portion.

6. A cementing plug, including a forward rigid head portion, a tail piece rigidly secured to and extending rearwardly from said head portion, an elastic inwardly compressible body having a socket receiving said tail piece, said body having an annular ange adapted for slidable sealing engagement with the wall of a well conduit and a trailing portion converging in a direction leading away from said head portion, and an elastic generally spherically curved seal on the forward surface of said head portion.

7. A top cementing plug, including a forward rigid valve head portion and an elastic rearward portion secured to said head portion and having an inwardly compressible main body, said body being adapted for slidable sealing engagement with the wall of a well conduit and being com pressible inwardly by hydraulic pressure out of such `sealing engagement around the entire circumference of the conduit, the maximum 'diameter of said head portion being substantially less than the maximum diameter of said body, and an elastic seal on the forward surface of said head portion.

8. A top cementing plug, including a forward rigid head portion, a tail piece rigidly secured to and extending rearwardly from said head portion, an elastic inwardly compressible main body having a socket receiving said tail piece, said body having an annular flange adapted for slidable sealing engagement with the wall of a well conduit and a trailing portion having an outer surface converging in a direction leading away from said head 'portion tobe acted on by hydraulic pressure to compress said body inwardly and remove'said iiange from sealing engagement with the wall of the well conduit, the maximum diameter of said head portion being substantially less than the diameter of said flange, and an elastic seal on the forward surface of said head portion.

REUBEN C. BAKER. J OHN R. BAKER.

References Cited in the file 0f this patent UNITED STATES PATENTS Number Name Date 2,004,606 Halliburton June 11, 1935 2,161,283 Crowell June 6, 1939 2,167,747 Dyer Aug. 1, 1939 2,179,812 Calkins Nov. 14, 1939 2,196,652 Baker Apr. 9, 1940 2,257,784 Brown Oct. 7, 1941 2,313,762 Midgett Mar. 16, 1943 2,370,833 Baker Mar. 6, 1945 2,493,650 Baker et al Jan. 3, 1950 

